var xScroll,
yScroll;
var windowWidth,
windowHeight;
var pageWidth,
pageHeight;
function getPageSize() {
    if (window.innerHeight && window.scrollMaxY) {
        xScroll = window.innerWidth + window.scrollMaxX;
        yScroll = window.innerHeight + window.scrollMaxY
    } else {
        if (document.body.scrollHeight > document.body.offsetHeight) {
            xScroll = document.body.scrollWidth;
            yScroll = document.body.scrollHeight
        } else {
            xScroll = document.body.offsetWidth;
            yScroll = document.body.offsetHeight
        }
    }
    if (self.innerHeight) {
        if (document.documentElement.clientWidth) {
            windowWidth = document.documentElement.clientWidth
        } else {
            windowWidth = self.innerWidth
        }
        windowHeight = self.innerHeight
    } else {
        if (document.documentElement && document.documentElement.clientHeight) {
            windowWidth = document.documentElement.clientWidth;
            windowHeight = document.documentElement.clientHeight
        } else {
            if (document.body) {
                windowWidth = document.body.clientWidth;
                windowHeight = document.body.clientHeight
            }
        }
    }
    if (yScroll < windowHeight) {
        pageHeight = windowHeight
    } else {
        pageHeight = yScroll
    }
    if (xScroll < windowWidth) {
        pageWidth = xScroll
    } else {
        pageWidth = windowWidth
    }
};